1. Field of the Invention
The present invention relates to a power-supplying member and a heating apparatus using the same, suitable for semiconductor manufacturing systems such as thermal chemical Vapor Deposition (CVD) systems and plasma CVD systems.
2. Description of the Related Art
There is conventionally known, as disclosed in Japanese Patent Application Laid-Open No. H5-326112, heating apparatuses (hereinafter referred to as “ceramic heaters”) comprise a ceramic base in which a heating resistor oz an electrode are embedded; a tubular supporting member which supports the ceramic base; and a power-supplying member which is disposed to a hollowed part in the tubular supporting member, and which supplies power to the heating resistor or the electrode. According to the ceramic heaters of the related art, an end of the power-supplying member formed from a nickel or a nickel-base alloy is connected to the heating resistor or the electrode, and the ocher end of the power-supplying member is connected to the power supply through the connector or the like.
However, according the ceramic heaters of the related art, the power-supplying member and the tubular supporting member are different in material and temperature in use. This brings about a problem that the difference between the power-supplying member and the tubular supporting member in amount of thermal expansion is large. In addition, as mentioned above, an and of the power-supplying member is connected to the heating resistor or the electrode, and the other end of the power-supplying member is connected to the power supply through the connector or the like. Moreover, the other end of the power-supplying member in supported and held by O-ring seal to hermetically hold a chamber.
For this reason, according to the ceramic heaters of the related art, as the power-supplying member cannot freely expand thermally in response to temperature change, excessive stress occurs in a joint part where the heating resistor or the electrode is joined to the power-supplying member. The occurrence of the stress brings about a problem that the stress disconnects a power-supplying member from the heating resistor or the electrode (terminal disconnection), and a problem that the stress causes critical cracks in the ceramic base in the vicinity of the joint part. Accordingly, the ceramic heaters of the related art have a problem in reliability.
It is an object of the present invention to provide a power-supplying member that can improve reliability of a heating apparatus and a heating apparatus using the same.